The use of skeletal implants is common in surgical repairs. Implants are employed in a variety of procedures such as spinal repair, knees, hips or shoulders and others. A common and most important feature of many implants is the integration of the implant into the skeletal structure. Mechanical fasteners, surface modifications, coatings, sutures and adhesives and other ways of affixing the device to the bone structure are used. These implants can be fashioned from human bone or other biological material or alternatively can be made from implantable grade synthetic plastics, ceramics or metals like stainless steel, titanium or the alloys of metals suitable for implantation.
One of the benefits of these plastic or metal implants is the strength and structure can be specifically designed to be even more durable than the bone being replaced.
As mentioned, one concern is properly securing the implant in place and insuring it cannot be dislodged or moved after repair. One of the best solutions to this issue is to allow the surrounding bone structure to grow around the implant and in some cases of hollow bone implants to allow new bone growth to occur not only around, but throughout the implant as well to achieve interlocked connectivity. Enhancing surface area by blasting, etching, or in some other way increasing the relative surface energy interface with the biologic component is desirable.
This is not particularly easy in many of the metal implants or hard plastic implants. In fact, the surface structure of the implant material is often adverse to bone formation. On some implant surfaces this may in fact be a desirable characteristic, but in those procedures where new bone growth formation is desirable this is problematic.
It is therefore an object of the present invention to provide an improved implant device that encourages new bone growth formation at selected surfaces of the device. The selected surfaces can be some or all external or internal exposed surface features of the implant device. The device with exposed surfaces that have selected surfaces for bone growth formation can be prepared by the methods as described below.
In addition to better activate a natural cellular response to new bone creation, it is a further object of the present invention to achieve an electrical conductivity at the surface of this improved implant device to react to low voltage stimulation which the body of a mammal naturally generates. While electrical conductivity is achieved in many metal implants such as titanium, it is not in plastics or allograft bone implants. It is therefore an object to create surface conductors in otherwise non-conductive implant materials.